Toluene → 1-ethyl-2-{[2-(1,3-thiazol-2-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]methyl}-1H-imidazo[4,5-c]pyridine

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Reaction Steps

To a mixture of N4-ethyl-pyridine-3,4-diamine (94 mg, 0.687 mmol) in CH2Cl2 (5 mL) at room temperature under N2 is added 2.0 M AlMe3 in toluene (0.43 mL, 0.858 mmol), and the resulting mixture is stirred at room temperature for 1 h. Next, a solution of (2-thiazol-2-yl-4-trifluoromethyl-imidazol-1-yl)-acetic acid methyl ester (100 mg, 0.343 mmol) in CH2Cl2 is added via cannula. The reaction mixture is then stirred at reflux overnight. After cooling to rt, it is treated with MeOH (˜1 mL)). The mixture is further diluted with 0.5 N aq NaOH (10 mL) and then stirred vigorously for 30 min. The mixture is then extracted thrice with CH2Cl2 containing some (˜5%) MeOH, and the combined extracts are dried over K2CO3 and concentrated. The crude mixture of 1-ethyl-2-{[2-(1,3-thiazol-2-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]methyl}-1H-imidazo[4,5-c]pyridine and N-(4-amino-pyridin-3-yl)-2-(2-thiazol-2-yl-4-trifluoromethyl-imidazol-1-yl)-acetamide is dissolved in AcOH (6 mL), and the resulting solution stirred at reflux overnight. The reaction mixture is then concentrated, and the residue is dissolved in CH2Cl2 and washed with 0.5 N aq NaOH. The aqueous layer is reextracted once with CH2Cl2, and the combined extracts are dried over K2CO3 and concentrated. The crude residue is purified by preparative TLC. Developing with 15:1 CHCl3-MeOH affords 1-ethyl-2-{[2-(1,3-thiazol-2-yl)-4-(trifluoromethyl)-1H-imidazol-1-yl]methyl}-1H-imidazo[4,5-c]pyridine. 1H NMR (CDCl3, 400 MHz) δ 9.10 (s, 1H), 8.47 (d, J=6.0 Hz, 1H), 7.88 (d, J=3.2 Hz, 1H), 7.58 (s, 1H), 7.48 (d, J=3.2 Hz, 1H), 7.31 (d, J=5.6 Hz, 1H), 6.37 (s, 2H), 4.31 (q, J=7.2 Hz, 2H), 1.24 (t, J=7.2 Hz, 3H) ppm.

Provenance & Evidence